Abstract
Magnetic reconnection is a fundamental physical process in planetary
magnetospheres, in which plasma can be exchanged between the solar wind
and a planetary magnetosphere, and material can be disconnected and
ultimately lost from a magnetosphere. Magnetic reconnection in a
planetary magnetotail can result in the release of plasmoids downtail
and dipolarizations planetward of an x-line. The signatures of these
products include characteristic deflections in the north-south component
of the magnetic field which can be detected by in-situ spacecraft. These
signatures have been identified by eye, semi-automated algorithms, and
recently machine learning methods. Here, we apply statistical analysis
to the most thorough catalogue of Kronian magnetospheric reconnection
signatures created through machine learning methods to improve
understanding of magnetospheric evolution. This research concludes that
no quasi-steady position of the magnetotail x-line exists within 70 R S.
This research introduces prediction equations to estimate the
distribution of duration of plasmoid passage over the spacecraft (N =
300∆t −1.3 , bin width = 1 min) and north-south field deflection (N =
52∆B −2.1 θ , bin width = 0.25 nT) expected to be identified by an
orbiting spacecraft across a year of observations. Furthermore, this
research finds a local time asymmetry for reconnection identifications,
with a preference for dusk-side over dawn-side. This may indicate a
preference for Vasyliunas style reconnection over Dungey style for
Saturn. Finally, through these distributions, the reconnection rate of
Saturn’s magnetotail can be estimated as 3.22 reconnection events per
day, with a resulting maximum mass loss from plasmoids of 34.4 kg s −1
on average, which is comparable with the magnetospheric mass loading
from Enceladus (8-250 kg s −1).